1Kernel driver ltc4261
2=====================
3 4Supported chips:
5 * Linear Technology LTC4261
6 Prefix: 'ltc4261'
7 Addresses scanned: -
8 Datasheet:
9http://cds.linear.com/docs/Datasheet/42612fb.pdf 10 11Author: Guenter Roeck <guenter.roeck@ericsson.com>
12 13 14Description
15-----------
16 17The LTC4261/LTC4261-2 negative voltage Hot Swap controllers allow a board
18to be safely inserted and removed from a live backplane.
19 20 21Usage Notes
22-----------
23 24This driver does not probe for LTC4261 devices, since there is no register
25which can be safely used to identify the chip. You will have to instantiate
26the devices explicitly.
27 28Example: the following will load the driver for an LTC4261 at address 0x10
29on I2C bus #1:
30$ modprobe ltc4261
31$ echo ltc4261 0x10 > /sys/bus/i2c/devices/i2c-1/new_device
32 33 34Sysfs entries
35-------------
36 37Voltage readings provided by this driver are reported as obtained from the ADC
38registers. If a set of voltage divider resistors is installed, calculate the
39real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the
40value of the divider resistor against the measured voltage and R2 is the value
41of the divider resistor against Ground.
42 43Current reading provided by this driver is reported as obtained from the ADC
44Current Sense register. The reported value assumes that a 1 mOhm sense resistor
45is installed. If a different sense resistor is installed, calculate the real
46current by dividing the reported value by the sense resistor value in mOhm.
47 48The chip has two voltage sensors, but only one set of voltage alarm status bits.
49In many many designs, those alarms are associated with the ADIN2 sensor, due to
50the proximity of the ADIN2 pin to the OV pin. ADIN2 is, however, not available
51on all chip variants. To ensure that the alarm condition is reported to the user,
52report it with both voltage sensors.
53 54in1_input ADIN2 voltage (mV)
55in1_min_alarm ADIN/ADIN2 Undervoltage alarm
56in1_max_alarm ADIN/ADIN2 Overvoltage alarm
57 58in2_input ADIN voltage (mV)
59in2_min_alarm ADIN/ADIN2 Undervoltage alarm
60in2_max_alarm ADIN/ADIN2 Overvoltage alarm
61 62curr1_input SENSE current (mA)
63curr1_alarm SENSE overcurrent alarm
64